Remove the hard core from the cabbage leaves and rinse them under running water.

Steam the cabbage leaves or microwave them in a plastic bag with residual water for 5 minutes until soft. Let them cool.

Chop the onion, zucchini, mushrooms, and green onions. Drain the tuna to remove excess oil.

Heat a pan with a small amount of oil and sauté the onion and zucchini.

Add the mushrooms to the pan and continue sautéing.

Add gochujang, miso paste, minced garlic, and water to the pan. Simmer until the mixture thickens.

Once the mixture has reduced, add the drained tuna and stir well.

Add the chopped green onions and lightly toss to finish the filling.

Lay the cooled cabbage leaves flat and spread them out.

Place a generous amount of the tuna filling onto the cabbage leaves.

Carefully roll the cabbage leaves from one end to the other.